Zih and Be Seen

I don't like being told how much to tip either. Tips are reserved for good service. If you give poor service a tip to reward this does not make sense to me. However, that being said I have only once in my life left a zero tip for bad service. I typically tip 18 to 20% and do the same when I'm in Mexico. I don't know why people (tourists) who visit there think that they can get away with tipping poorly. It is so disrespectful in my mind.... but, then again, so are the employers who employ these people. Shame on them for the low salaries they pay their employees.